Ah, tomatoes — that heavenly slice of summer. There’s no other vegetable — well, technically it's a fruit — that tastes so wonderful when home grown versus store bought. But if you’ve tried to grow them here in Tucson, you know they can be finicky. Chances are you’ve had a little success — and a lot of failures.

Last summer my tomatoes did really well in the spring — they grew fast, bushed out nicely and produced lots of leaves. But there weren’t many flowers and they didn’t develop into actual fruit. Sound familiar?

If you have a chance to take a class at Harlow Gardens or another nursery, do take advantage of it. People at a recent class all seemed to have a lot of "ah-hah" moments. The follow-up questions were good, and our instructor covered in-ground and container gardening, too.

So read on for some expert advice from the class; after 20 minutes of listening to garden guru Carolyn Smith I had figured out my biggest mistake. You’ll probably recognize your own mistakes in the following list.


It’s OK to plant now, but some gardeners did so in February, especially given our early spring. March 15 is our average frost-free date but it’s not a hard and fast guideline, so now's the time to get those transplants in.

What's new:

New and gaining in popularity are grafted tomato plants. Why? They have a sturdier rootstock that can take our brutal summer heat. They grow faster, produce more fruit and are said to be more resistant to diseases and pests.

Look for both cherry and regular grafted tomatoes in nurseries. How do you know they’re grafted? They should be marked as such, plus if you look closely at the stem you’ll see a little clip. You should leave the clip alone; it will pop off by itself as it grows, Carolyn says.

As you’d expect, they cost more — twice as much, in fact. But considering what you’d pay per tomato at the farmers market, it’s probably worth it.

Where to plant:

For your summer garden, try to get some afternoon shade. You want plants to get plenty of morning sun — at least four to six hours a day. A deciduous tree that casts shade later in the day would work, or use a shade cloth.

  • Container tip: Your pots should be 20 inches in diameter minimum and at least 15 inches deep, unless you’re growing a compact variety. If you’re using containers, choose the smaller varieties. Also it should be noted: plant just one plant per pot and don’t plant anything else with it or it’ll compete for water and nutrients.
James Wood / Arizona Daily Star 2009

Tilling, fertilizing and planting

  • Till 2-3 feet down for your summer garden. (Winter gardens don’t have to be as deep.) Add 3-4 inches of organic compost and till that in. Here’s my big mistake: Don’t use manure for summer crops like tomatoes, even if it’s well aged. What’s the problem with manure? It’s too “hot” for the roots and can lead to blossom-end rot. (More on that later.) Use compost instead or try worm castings. They keep the soil loose and add beneficial nutrients. (A couple of live worms would be a bonus.) Again, organic compost is best because it releases nutrients slowly over the season.
  • Don’t use synthetic fertilizers. It was music to my organic ears to hear Carolyn say that. Why? Organic matter helps build the soil, doesn’t harm good microorganisms and releases nutrients slowly. It rarely burns the plants — and only if you overapply it. So follow directions. When it comes to fertilizer, “More is not better.” Well said, Carolyn. Also, fertilize your heavy feeders regularly throughout the summer. I usually make a compost tea and water it in once a month or so.
  • Pinch off the very bottom leaves and put the plant deeper in the ground than it was in the pot — up to the second set of leaves. Stake each plant to keep it from flopping over.